docs: def hash(self):
          """Create a unique hash for what is currently playing.
  
          The hash is based on title, artist, album and total time. It should
          always be the same for the same content, but it is not guaranteed.
          """
          base = '{0}{1}{2}{3}'.format(
              self.title, self.artist, self.album, self.total_time)
          return hashlib.sha256(base.encode('utf-8')).hexdigest()